OF ARTS AND SCIENCES : JANUARY 26, 1870. 183 



and scarcely rigid divisions of the panicle; the ultimate ones or pedicels 

 less refracted, sometimes a full inch in length, commonly half an inch, 

 and therefore many times longer than the fewer-flowered involucre. 



-i— +~ Effusa, sa?pius ramosissima, pedicellis nunquam deflexis. In- 

 volucra haud linea longora, interdum minuta, pauci-subpluriHora. 

 Perigonium basi fere semper obtusissimum. Annua ; folia radi- 

 calia vel subradicalia, rotundata, nunc basi cordata petiolata. 



++ Subtus albo-lanata, supra plerumque floccosa. Perigonia involucro 

 grossius 5 - 6-dentato haud longiora. Bractea2 sajpissime intus 

 lanatre. 



a. Pedicelli breves (lin. 1-5 longi) cum panicula tota rigiduli. 

 Perigonii glaberrimi segmenta maxime disparia. 



65. E. rotundifolium, Benth. in DC. 1. c. Humile ; foliis supra 

 mox denudatis ; panicula e collo ramosissima (spithamoea) rigidula 

 floribunda; involucris late campanulatis subplurifloris ; bracteolis parce 

 phimosis ; perigonio albo glaberrimo parum ultra medium 6-Jido, seg- 

 ments exterioribus flabelliformi-dilatatis retusis, interioribus anguste 

 oblongis. — Western borders of Texas and adjacent parts of New 

 Mexico, "Wright, Bigelow, Thurber, Parry. Involucre seldom a line 

 long, almost of the same breadth. Flowers three fourths of a line 

 long, with a broadly campanulate base, and the outer segments much 

 dilated upwards, so as to be usually much broader than long ; the 

 inner ones small and narrow. 



b. Pedicelli tenues saepissime capillares, alares semi-sesquipollicares. 

 Perigonia basi tenuiter pilosula vel glabra. Herbce tenellce, 

 cyma 2-3-chotoma tenera cum scapo spithama?a, in depauperatis 

 subsimplici; foliis lamina semipollicari seu minori. 



66. E. Thurberi, Torr. Bot. Mex. Bound, p. 176. Foliis rotun- 

 datis ssepius rugosis ; scapo 1 - 2-pollicari primum lanuloso ; bracteis 

 3 - 4-natis conspicuis calyculiformibus ; involucro late turbinato- 

 campanulato 10-18-floro; bracteolis vix ullis; perigonio albo (fruc- 

 tifero lineam longo) 5-partito basi brevi extus minutissime parceque 

 hirsutulo, segmentis valde disparibus panduriformibus, exterioribus 

 lobo terminali maximo rotundato (demum latiore quam longo) in 

 centro tenuiter arachnifero, auriculis basim versus parvis, interioribus 

 subhastato-lanceolatis parvulis superne vix dilatatis. — California, in 

 sandy ravines near San Pasqual, Thurber. Los Angeles, Wallace. 



